src/hotspot/cpu/x86/c1_LIRAssembler_x86.cpp

@@ -1633,11 +1633,11 @@
      }
      __ allocate_array(op->obj()->as_register(),
                        len,
                        tmp1,
                        tmp2,
-                       arrayOopDesc::header_size(op->type()),
+                       arrayOopDesc::base_offset_in_bytes(op->type()),
                        array_element_size(op->type()),
                        op->klass()->as_register(),
                        *op->stub()->entry());
    }
    __ bind(*op->stub()->continuation());

@@ -3068,10 +3068,11 @@
    Register src_pos = op->src_pos()->as_register();
    Register dst_pos = op->dst_pos()->as_register();
    Register length  = op->length()->as_register();
    Register tmp = op->tmp()->as_register();
    Register tmp_load_klass = LP64_ONLY(rscratch1) NOT_LP64(noreg);
+   Register tmp2 = UseCompactObjectHeaders ? rscratch2 : noreg;
  
    CodeStub* stub = op->stub();
    int flags = op->flags();
    BasicType basic_type = default_type != nullptr ? default_type->element_type()->basic_type() : T_ILLEGAL;
    if (is_reference_type(basic_type)) basic_type = T_OBJECT;

@@ -3259,17 +3260,11 @@
  
    if (flags & LIR_OpArrayCopy::type_check) {
      // We don't know the array types are compatible
      if (basic_type != T_OBJECT) {
        // Simple test for basic type arrays
-       if (UseCompressedClassPointers) {
-         __ movl(tmp, src_klass_addr);
-         __ cmpl(tmp, dst_klass_addr);
-       } else {
-         __ movptr(tmp, src_klass_addr);
-         __ cmpptr(tmp, dst_klass_addr);
-       }
+       __ cmp_klass(src, dst, tmp, tmp2);
        __ jcc(Assembler::notEqual, *stub->entry());
      } else {
        // For object arrays, if src is a sub class of dst then we can
        // safely do the copy.
        Label cont, slow;

@@ -3425,22 +3420,17 @@
  #ifdef _LP64
      if (UseCompressedClassPointers) {
        __ encode_klass_not_null(tmp, rscratch1);
      }
  #endif
- 
      if (basic_type != T_OBJECT) {
- 
-       if (UseCompressedClassPointers)          __ cmpl(tmp, dst_klass_addr);
-       else                   __ cmpptr(tmp, dst_klass_addr);
+       __ cmp_klass(tmp, dst, tmp2);
        __ jcc(Assembler::notEqual, halt);
-       if (UseCompressedClassPointers)          __ cmpl(tmp, src_klass_addr);
-       else                   __ cmpptr(tmp, src_klass_addr);
+       __ cmp_klass(tmp, src, tmp2);
        __ jcc(Assembler::equal, known_ok);
      } else {
-       if (UseCompressedClassPointers)          __ cmpl(tmp, dst_klass_addr);
-       else                   __ cmpptr(tmp, dst_klass_addr);
+       __ cmp_klass(tmp, dst, tmp2);
        __ jcc(Assembler::equal, known_ok);
        __ cmpptr(src, dst);
        __ jcc(Assembler::equal, known_ok);
      }
      __ bind(halt);

@@ -3532,10 +3522,24 @@
    if (info != nullptr) {
      add_debug_info_for_null_check_here(info);
    }
  
  #ifdef _LP64
+   if (UseCompactObjectHeaders) {
+     Register tmp = rscratch1;
+     assert_different_registers(tmp, obj);
+     assert_different_registers(tmp, result);
+ 
+     // Check if we can take the (common) fast path, if obj is unlocked.
+     __ movq(result, Address(obj, oopDesc::mark_offset_in_bytes()));
+     __ testb(result, markWord::monitor_value);
+     __ jcc(Assembler::notZero, *op->stub()->entry());
+     __ bind(*op->stub()->continuation());
+     // Fast-path: shift and decode Klass*.
+     __ shrq(result, markWord::klass_shift);
+     __ decode_klass_not_null(result, tmp);
+   } else
    if (UseCompressedClassPointers) {
      __ movl(result, Address(obj, oopDesc::klass_offset_in_bytes()));
      __ decode_klass_not_null(result, rscratch1);
    } else
  #endif